Git Identify Obsolete Branches

Git Identify Obsolete Branches

Scans the git repository to identify branches that can be safely removed based on merge status and inactivity period.

When to Use This Skill

• User asks to "identify obsolete branches"
• User wants to "find stale branches" or "list deletable branches"
• Scheduled daily/weekly branch cleanup
• After a PR is merged and branches need review
• User wants to review branches before deletion

Prerequisites

• Git repository initialized
• Network access to fetch latest remote information
• main or master branch as the base branch

Workflow

1. Fetch latest remote information

git fetch --all --prune

2. Get the base branch name (main or master)

git branch --show-current

3. Identify branches merged into main/master

git branch --merged main

4. Identify branches merged into main/master (alternative)

git branch --merged master

5. Find branches inactive for 30+ days

Bash:

for branch in $(git for-each-ref --format='%(refname:short)' refs/heads/); do
  last_commit=$(git log -1 --format='%ai' "$branch" 2>/dev/null)
  if [ -n "$last_commit" ]; then
    days_since=$(($(date +%s) - $(date -d "$last_commit" +%s) / 86400))
    if [ "$days_since" -gt 30 ]; then
      echo "$branch|$last_commit|$days_since"
    fi
  fi
done

PowerShell:

git for-each-ref --format='%(refname:short)' refs/heads/ | ForEach-Object {
    $branch = $_
    $lastCommit = git log -1 --format='%ai' $branch 2>$null
    if ($lastCommit) {
        $commitDate = [DateTime]::Parse($lastCommit.Trim())
        $daysSince = ((Get-Date) - $commitDate).Days
        if ($daysSince -gt 30) {
            "$branch|$lastCommit|$daysSince"
        }
    }
}

6. Combine merged and inactive branches

Filter the output to show branches that are:

• Merged into main/master, OR
• Inactive for more than 30 days

Exclude protected branches (main, master, develop, release/, hotfix/)

7. Generate report

Create a structured report with:

• Branch name
• Last commit date
• Days since last activity
• Reason (merged/inactive)

Output Format

=== OBSOLETE BRANCHES REPORT ===
Generated: [timestamp]

Branch Name          | Last Commit   | Days Inactive | Reason
---------------------|---------------|---------------|------------------
feature/old-thing    | 2026-06-01    | 44            | Merged
wip/experiment       | 2026-05-10    | 66            | Inactive > 30 days
fix/old-bug          | 2026-06-15    | 30            | Merged

Total branches identified: 3

Safety Notes

• This skill ONLY identifies branches - it does NOT delete anything
• Always exclude protected branches from deletion candidates
• Present the report to the user for confirmation before deletion
• Branches that have never been pushed to remote are marked as "local-only"